Ultrasound measurements of vein collapse to predict low blood pressure after spinal anesthesia

Evaluation of Inferior Vena Cava and Femoral Vein Collapsibility Indices for Predicting Post-Spinal Hypotension in Patients Undergoing Transurethral Prostate Resection: A Prospective Observational Study

Observational Antalya Training and Research Hospital · NCT07497295

We will test whether ultrasound measurements of the inferior vena cava and femoral vein before spinal anesthesia can predict low blood pressure in men having TUR‑P.

Quick facts

Study typeObservational
Enrollment110 (estimated)
Ages18 Years to 75 Years
SexMale
SponsorAntalya Training and Research Hospital Government
Locations1 site (Antalya, Muratpasa)
Trial IDNCT07497295 on ClinicalTrials.gov

What this trial studies

This is a prospective observational study at Antalya Training and Research Hospital enrolling adults scheduled for elective transurethral resection of the prostate under spinal anesthesia. Before anesthesia, clinicians will use M‑mode ultrasonography in the supine position to record maximum and minimum diameters of the inferior vena cava and the femoral vein and calculate collapsibility indices. Standard hemodynamic measurements will be recorded before and after spinal anesthesia without a fluid preload, and occurrences of post‑spinal hypotension will be identified using predefined criteria. The study will compare the diagnostic performance of IVC collapsibility index and femoral vein collapsibility index and seek cutoff values that predict hypotension.

Who should consider this trial

Good fit: Adult men aged 18–75 scheduled for elective TUR‑P under spinal anesthesia with ASA physical status I–III who can give informed consent and cooperate with ultrasound measurements.

Not a fit: Patients with BMI >30, severe or unstable cardiovascular disease, implanted cardiac devices, emergency surgery, or other exclusion conditions are not eligible and would not benefit from these predictive ultrasound measures in this protocol.

Why it matters

Potential benefit: If successful, this approach could help identify patients at high risk for post‑spinal hypotension so clinicians can target preventive measures and improve perioperative safety.

How similar studies have performed: Prior small studies have shown mixed but promising results for IVC collapsibility predicting post‑spinal hypotension, while femoral vein collapsibility is less well studied and relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Adult patients aged 18-75 years
* American Society of Anesthesiologists (ASA) physical status I-III
* Scheduled for elective transurethral resection of the prostate (TUR-P)
* Planned spinal anesthesia
* Ability to provide written informed consent

Exclusion Criteria:

* Refusal to participate in the study
* Body mass index (BMI) \>30 kg/m²
* Use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers
* Emergency surgery
* Baseline systolic arterial blood pressure \<90 mmHg or mean arterial pressure \<70 mmHg
* Major peripheral vascular disease or severe cardiovascular disease
* Unstable angina or left ventricular ejection fraction \<40%
* Chronic respiratory disease
* Increased intra-abdominal pressure
* Autonomic nervous system disorders
* Implanted pacemaker or implantable cardioverter-defibrillator
* Anticipated difficult airway
* Cognitive impairment or inability to cooperate

Where this trial is running

Antalya, Muratpasa

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Post Spinal Anaesthesia HypotensionTransurethral Resection of the ProstateSpinal AnesthesiaPost-Spinal HypotensionUltrasonographyInferior Vena Cava Collapsibility IndexFemoral Vein Collapsibility Index
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.